Optically controlled silicon carbide and related wide-bandgap transistors and thyristors
AssigneePower Integrations, Inc.
InventorMichael S. Mazzola
Life of this patent
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Abstract
An optically active material is used to create power devices and circuits having significant performance advantages over conventional methods for affecting optical control of power electronics devices and circuits. A silicon-carbide optically active material is formed by compensating shallow donors with the boron related D-center. The resulting material can be n-type or p-type but it is distinguished from other materials by the ability to induce persistent photoconductivity in it when illuminated by electromagnetic radiation with a photon energy in excess of the threshold energy required to photoexcite electrons from the D-center to allowed states close to the conduction band edge, which varies from polytype to polytype.
Claims14
A method of making a semiconductor device comprising:
- forming a first layer of n-type SiC semiconductor material on an n-type conducting substrate;
- forming an optically active, semi-insulating SiC region on the first layer of n-type SiC semiconductor material;
- forming a second layer of n-type SiC semiconductor material on the optically active, semi-insulating SiC region;
- selectively etching through the second layer of n-type SiC semiconductor material, the optically active, semi-insulating SiC region and the first layer of n-type SiC semiconductor material in a peripheral region of the device to form a mesa having sidewalls;
- and
- depositing dielectric material on the sidewalls of the mesa.
A method of making a semiconductor device comprising:
- forming a first layer of n-type SiC semiconductor material on an n-type conducting substrate;
- forming a second layer of n-type SiC semiconductor material on the first layer of n-type SiC semiconductor material;
- forming a third layer of n-type SiC semiconductor material on the second layer of n-type SiC semiconductor material;
- selectively etching through the third layer of n-type SiC semiconductor material to expose portions of the underlying second layer of n-type SiC semiconductor material thereby forming trenches;
- selectively implanting boron in the exposed portions of the underlying second layer of n-type SiC semiconductor material at the bottom of the trenches to form optically active, semi-insulating SiC regions in the second layer of n-type SiC semiconductor material;
- and
- depositing dielectric material in the trenches.
A method of making a semiconductor device comprising:
- forming a drift layer of n-type SiC semiconductor material on an n-type conducting substrate;
- forming a layer of p-type SiC semiconductor material on the drift layer, wherein the p-type layer is doped with a dopant other than boron;
- implanting boron in the layer of p-type SiC semiconductor material;
- selectively etching through the layer of p-type SiC semiconductor material to form first etched regions;
- epitaxially growing a channel layer of n-type SiC semiconductor material in the etched regions and on the surface of the layer of p-type SiC semiconductor material adjacent the etched regions, wherein boron diffuses into the channel layer during epitaxial growth of the channel layer to form one or more optically active, semi-insulating SiC regions in the channel layer;
- and
- epitaxially growing a source layer of n-type SiC semiconductor material on the channel layer.
Dependencies are inferred from the claim text.